Fats contribute from 30% to 40% of the total calories consumed by most Americans. One of the most common nutritional problems in the United States today is obesity, which results from the consumption of more calories than are expended. Consumption of fat is related to many disease states, such as heart disease. Successful reduction of fat consumption has not been achieved because of the dietary habits of the traditional American. Therefore, the search for fat substitutes or low calorie fats has attracted attention in recent years.
Among the possible low-calorie fats or fat substitutes synthesized to date are polyglycerol esters, sucrose polyesters (SPE), neopentyl-type alcohols and other sugar derivatives such as sorbitol and mannitol, glycerol dialkyl ethers, triglyceride esters of alpha carboxylic acids, diglyceride esters of short-chain dibasic acids, trialkoxytricarballyate, polydextrose, palatinose, polygalactose, N-oil (tapioca dextrin), microbiologically derived products, nonabsorbable synthetic polymers with properties similar to edible oil, tree-derived products, low-metabolized natural fats and oils, biopolymers, branched polysaccharides and jojoba oil. Many of these are reviewed by Harem, J. Food Sci. 49 419 (1984).
The present inventors have previously discovered a class of fat substitute materials comprising alkyl and hydroxyalkyl glycoside fatty acid polyesters, some of which are disclosed in U.S. Pat. Nos. 4,840,815 and 4,942,054.
Another class of fat substitute materials of note are sucrose fatty acid polyesters, which are disclosed in U.S. Pat. Nos. 3,600,186, 4,368,213, and 4,461,782.
A significant problem associated with the use of liquid fat substitute materials, i.e., those having a melting point at or below body temperature of about 37.degree. C., is an undesired "laxative" effect, which is manifested in leakage of the liquid fat substitute material through the anal sphincter after ingestion. As is common in the art of fat substitute materials, the phrases "laxative effect" and "anal leakage effect" are equivalent terms for the present purposes.
Previously, in U.S. Pat. No. 4,005,195, it has been disclosed that the laxative effect can be reduced or eliminated by combining higher melting material, such as solid triglycerides and solid sucrose polyesters, with the liquid polyesters. Such known anti-laxative agents are disclosed as being included at levels of at least 10%, and preferably at least 20%, of the nondigestible fat substitute. Another approach to preventing the undesirable laxative effect is to formulate the fat substitute materials to be completely solid at body temperature.
Completely solid esters and solid triglycerides used as anti-laxative agents have drawbacks when used in low calorie food compositions. For example, the high solids content can result in a "waxy" feel in the mouth when ingested. It would be desirable to have a fat substitute composition that is effective at reducing calories and cholesterol and also has a relatively low solids content, so that it does not feel waxy in the mouth. At the same time, it is also important that the fat substitute composition not exhibit the laxative side effect. The overall content of the anti-laxative agent in the fat substitute composition as a percentage of the non-digestible fat substitute material is desirably included at the lowest safe and effective level, to effectively reduce leakage without creating a waxy mouthfeel, while also allowing the highest possible degree of fat substitution.
Accordingly, one object of the present invention is to provide agents that exert an anti-laxative effect when used in combination with fat substitute materials in foods.
It is yet another object of the present invention to provide new methods for reducing the laxative side effects associated with fat substitute materials as compared to the prior art.
The above and other objects of the present invention as will hereinafter become more readily apparent have been achieved by the present invention, which is disclosed in detail herein.